Improvement in rotary pumps



vspace on the opposite side at CZ.

UNITED STATES PATENT OFFICE.

FERDINAND ROOHOV, OF NEV YORK, N. Y.

IMPROVEMENT IN ROTARY PUMPS.'

Specification forming part of Letters Patent No. 33,961 dated December 17, 1861.

To a/ZZ whom, t may concern.-

Beit known that I, FERDINAND RooHow, of the city and State of New York, have invented a certain new and useful Improvement in Rotary Pumps; and I do hereby declare that the following is a full, clear, and exact description thereof, and of its construction and mode or manner of operation, reference being had to the accompanying drawings, and to the letters of reference marked thereon, making a part of this specification.

Figure l is a sectional view through the line C D of Fig. 2. Fig. 2 is a sectional View through the line A B, Fig. 1. Fig. 3 is a side elevation.

The whole machine or apparatus consists of a hollow inclosing-shell of an irregular curve, two opposite side pieces, and a revolving shaft, invwhich are movable pistons or abutments. All the several parts can be easily cast, and none are liable to get out of order or subject to much wear.

On the inclosingshell A are cast the supporting-feet l 1 and two openings 2 2, which are respectively the inlet and outlet of the pump. The two side pieces S S are screwed tightly to the shell by bolts b l) b b, and to secure them in a permanent position they are recessed in the shell, as shown at ffff, and between the parts are put pieces u u u u of rubber or other packing.

The shaft R extends through the shell A and is placed eccentrically within it, the center or axis of such shaft being at O', as shown in Fig. l, instead of at O, which would be the center of the shell A if it was cylindrical, and the side pieces S S, which furnish the bearings of the shaft, are bored out eccentrically through O', as seen more plainly in Fig. 3. The shaft R is prolonged at either end, as seen in Fig. 2, to receive the power by which it is driven, and is so placed within the shell A as to al` most but not quite touch such shell at the point a, Fig. 1, and leave the largest open The extent of this space will be controlled by the relative size of the shell A and shaft R; but it will always be such that the space will be double the eccentricity O O.

Through that part of the shaft R within the shell A there are made two slots at right angles with each other to receive the two slides or pistons o fu, which are flat pieces of solid metal or other suitable material, and which have a part taken out in their middle, as seen in Figs. l and 2, so that they can move backward and forward through each other, keeping their respective positions at right angles to each other. One slide or piston r, Fig. 2, is taken out in the middle, so that when it is put in the shaft the other piece, which is in two parts, can be inserted from both sides, and to connect such two parts together, in one there are fixed two taps tt, Figs. l and 2, and in'the other correspond- Ving holes, by which the two parts are made to work as one piece. These two slides are also of equal length.

In some rotary pumps or engines, where the shaft has been concentric with it, eccentricity has been given to the inclosing-shell by lilling in one of the inner sides of the inclosingshell; but this adds much to the cost of the machine and lessens its efliciency. In my in` vention the required eccentricity or irregularity'of outline is obtained by the shapeand construction of the shell itself, without any filling or inserting, the same being bored out or shaped to the required form, whereby it is both cheaper in construction and more certain and perfect in operation. These slides or pistons have on every side packings p p p p, Fig. l, fixed in grooves made in them, and

which extend down as far as the dotted lines Z Z Z Z, so as to cause the slide to move tightly against the shell and side pieces S S. The slots in the shaft R must therefore be of exactly thesame length as the rectangular distance between such side pieces. In order to secure proper strength to the shaft R and permit the making of the two slots for the pistons, as above described, the shaft is enlarged on the outside of the shell in a cylindrical form, as seen more plainly in Fig. 2.

The bore of the shell is not exactlya circle, as the revolving shaft R is placed eccentrically within it, and the slides or pistons b b, which, as before stat-ed, are always of the same length, must always just touch the shell A with their opposite ends. The bore of the shell must therefore be eccentric. The construction of the curve may be easily found by drawing lines, as represented in Fig. l, through the center O, and making such lines, so far as they are inside the shell, of an equal length and all equal to the diameter c d; but such lines should be symmetrically distributed on eitherside of the diameter o; d. A uniform curve connecting the ends of these lines will represent the profile of the bore of the shell.

In Fig. I the line A B represents the axis or diameter of the irregular curve or bore of the shell A, and such curveis symmetrical on each side of such axis. The point O is in such axis A B, but is not in the center of it, but is so taken that all the lines passing through it and touching the opposite sides of the irregular curves will be equal in length to such axis.

The openings for the inlet and outlet are so arranged in respect to the shell that one of the slides' or pistons shall always be between them, and thus separate the inlet from the outlet, and it will be seen that at every quar ter-revolution of the shaft there will be discharged a section equal toQ, less the small quantity in the opposite space q, provided the apartment Q is tight, so as to keep the fluid atthe pressure it is in the apartment without loss. To secure this end-that is, keep the apartment Q tight-theslides or pistons must move closely enough in the slots so that no water can pass by them, and this can be effected without the use of packing and by merely making such slots true. To prevent any leakage on the sides of the .shaft between such shaft and the side pieces I place two flexible rings of leather or other snitable packings p p p p', which are held or fixed to the shaft by small Wroughtiron rings or bands r r r r. Slight recesses for,such packings are made in the side pieces, as will be seen in Fig. 2, and the inside pressure itself tends to keep such packing close against the side pieces and prevent any leak. These rings p revolve in grooves or recesses turned in the side pieces, so that the outer surfaces of such rings are always uniform with the side of faces. The packings pp of the slides or pistons c c extending down on their sides have also the effect to keep tight the sides of the apartment Q. These packings p and p are therefore sufficient against any pressure from the inside of the pump. To prevent any air entering the suction-apartment between the packing-rings pp and the side pieces, an elastic packing of hemp or any other suitable material q q q q is set in the side pieces, as shown in Fig. 2. No stuffingboxes are required, as the part has not to he kept tight against pressure.

The improvement herein described and illustrated has reference to pumps or apparatus for forcing and elevating iuids; but the principal and distinguishing characteristics of the improvement before described may be applied with great advantage in the construction of steam and caloric engines, and in water meters and gas-meters, with slight alteration in the arrangement and combination of the parts and the application of the packing, duc. Such and other applications of the principle of my improvements I reserve for other applications for patents should I deem it advisable. It is also a matter immaterial whether the shell is fixed and the shaft revolves, or the shaft is lixed and the shell is made to revolve.

I do not claim, generally, arranging an inclosing-shell and an inclosed shaft or cylinder eccentrically in respect to each other.

What I claim as my inve tion, and desire to secure by Letters Patent, is*

l. Constructing the inclosing shell or case A of an eccentric or irregular curve such that Vall lines drawn from its opposite sides and through any one and the same point 0 in the axis or diameter of such curve, but at one side of the center of such axis, shall be of equal length, so that abutlnents or pistons 'u 0, of the same length with such axis or diameter revolving in such` shell and passing through a shaft or cylinder having the center of its axle in such point O', will always be in contact with the sides of the shell Without the use of any device to vary their length.

2. The combination of the shell or case A, when so constructed, with the inclosed shaft or cylinder R and its movable solid pistons u .fu arranged in respect to such shell, substantially as described.

3. The application and use of the packingrings p p and elastic packing q q, in combination with the shaft R and side pieces S S, substantially as and for the purposes set forth.

4. The whole machine or apparatus constructed substantially as and for the purposes set forth.

- FERDINAND ROCHOW. Witnesses:

S. D. LAW, L. BABBITT. 

